Christianity is not a religion which promotes isolation. It promotes fellowship and unity.
Often in life we find there are goods which the value of is diminished when there are many examples. If there were a thousand Mona Lisa paintings each an exact replica painted by the same artist each painting would be of little interest.
Rarity often heightens the value of things in the world. Christianity it is the opposite. It is fellowship and sharing which heightens the value.
The nature of grace is that it is free and infinite. You cannot hide it in isolation if you have it. It must be shared.
Grace which is hidden is lessened because in hiding the grace we lose track of its meaning. You see we don't simply believe things because we believe them; we believe things because we do them.
If we hide grace and act as if it is not important to share eventually our understanding of grace will weaken and we will be the poorer for it. Grace which we do not have some desire to share is not grace which is properly understood.
Grace is most glorious when shared and sharing grace increases its worth, not diminishes it.